This invention relates to apparatus for automatically polishing surfaces, and more particularly to apparatus for automatically polishing surfaces of vehicles such as automobiles.
Polishing surfaces such as the finished surfaces of automobiles necessitates the application of a polish, wax or cleaner to the surface and subsequently removing the residue. As used herein "polish" means any polish, wax, cleaner, or similar substance, or combinations thereof. The polish application stage should include sufficient frictional contact between the applicator and the surface to allow the polish to interact with the finish to remove discoloration and other blemishes which mar the finish. In other words it is generally desirable that the polish be "rubbed-in" to the surface. The polish removal stage should also include frictional contact with the surface in order to properly buff or polish it.
During both the polish application and removal stages, care must be exercised to prevent excessive heat from being generated by the frictional contact with the finished surface, and to avoid scratching or otherwise damaging the surface. Whether a polish is being applied or removed by a cloth or brush, and whether manually or automatically operated, the heat generated by friction tends to be held in or trapped against the surface. Excessive heat may cause permanent damage to a finished surface, as by burning off a portion of the paint or other finish. Naturally, this problem is much less acute when polish is applied and removed by a hand-held cloth. While limitations of the physical strength and stamina of a person hand-polishing a surface lessens the likelihood that the finish will be damaged, those same factors restrict the speed and uniformity with which the surface may be polished. On large surfaces, such as the surfaces of the body of automobiles and other vehicles, such limitations on the speed and uniformity of the polishing operation, as well as the physical strain on the persons involved, militates against hand-polishing on a large-scale basis.
Although hand-held machines for applying and removing polish may somewhat reduce the human labor factor and increase the speed of the operation, their use requires considerable skill in order to prevent damaging a finished surface. Such devices, which for example may comprise a rotating or vibrating pad, tend to trap heat against the surface. The operator must use enough pressure for a sufficient time to effect a polished surface. Too much pressure or too long a time spent in one area may be disastrous for the finish. Uneven pressure may also result in circular marks in the polished finish, commonly referred to as swirl marks. And the human labor factor is still too great and the speed too slow for economical large-scale polishing operations.
An automatic surface polishing system especially adapted to polish large surfaces, such as those of automobiles, quickly, and with uniformity, and without damaging the finish, is needed in order to permit large-scale polishing of such surfaces on an economical basis. This invention fulfills that need.
Automatic car washing systems are well known. Numerous ways have been devised to wash and dry vehicles, including the use of strategically spaced water spray nozzles, brushes and blowers, and rather sophisticated mechanical and electrical controls therefor. Some automatic car washing systems are also equipped to spray a liquid wax or polish onto the vehicle during the operation. These so-called waxing operations do not use any frictional contact in applying the material or in removing the residue. Application and removal are both inadequate.
Rotating washing brushes are used in automatic car wash systems, but rotating brushes or pads for polishing do not achieve the results of the present invention. Rotating brushes or pads tend to cause scratching and localized over-heating of the surface with consequent damage to the finish, and they are not well adapted for use with the irregular and contoured surfaces presented by many vehicles. Moreover, the polish tends to rapidly accumulate on such buffers, necessitating frequent cleaning in order to assure a proper buffing operation. The present invention overcomes these problems and provides a fast, efficient polishing system suitable for use as a mass vehicle-polishing installation.